BACKGROUND: Much attention has been directed to the induction of arginase I in the lung of asthmatic mice. However, there is no agreement on the changes of serum arginase activity in asthmatic patients among previous studies. OBJECTIVES: The aim of this study was to evaluate the clinical relevance of serum arginase I in asthmatic patients. METHODS: Serum arginase I was examined cross-sectionally in non-smoking asthmatic patients (n = 23) and healthy individuals (n = 30) using enzyme-linked immunosorbent assay (ELISA) and its correlations with several clinical parameters were investigated. RESULTS: Serum levels of arginase I were significantly increased in asthmatic patients (mean ± SD 67.4 ± 41.0 ng/mL) compared with healthy controls (27.2 ± 12.9 ng/mL). In healthy controls, a difference in arginase I levels was not observed between sex groups but was observed between age groups. In asthmatic patients, serum arginase I levels were not different between groups of age, sex, and inhalation steroid therapy but were different between groups of atopic status. Non-atopic asthmatic patients revealed significantly high serum arginase I levels compared with atopic asthmatic patients and healthy controls although no difference was observed between atopic asthmatic patients and healthy controls. Spearman's correlation analysis showed that serum arginase I level had a significant negative correlation with age and a positive correlation with red blood cell numbers in healthy controls, whereas in asthmatic patients, it had significant positive correlations with alanine aminotransferase (ALT), high-sensitivity C-reactive protein (hs-CRP) and a negative correlation with immunoglobulin-E (IgE). CONCLUSIONS: High serum arginase I levels in asthmatic patients may be associated with airway inflammation in non-atopic asthma.
BACKGROUND: Much attention has been directed to the induction of arginase I in the lung of asthmatic mice. However, there is no agreement on the changes of serum arginase activity in asthmatic patients among previous studies. OBJECTIVES: The aim of this study was to evaluate the clinical relevance of serum arginase I in asthmatic patients. METHODS: Serum arginase I was examined cross-sectionally in non-smoking asthmatic patients (n = 23) and healthy individuals (n = 30) using enzyme-linked immunosorbent assay (ELISA) and its correlations with several clinical parameters were investigated. RESULTS: Serum levels of arginase I were significantly increased in asthmatic patients (mean ± SD 67.4 ± 41.0 ng/mL) compared with healthy controls (27.2 ± 12.9 ng/mL). In healthy controls, a difference in arginase I levels was not observed between sex groups but was observed between age groups. In asthmatic patients, serum arginase I levels were not different between groups of age, sex, and inhalation steroid therapy but were different between groups of atopic status. Non-atopic asthmatic patients revealed significantly high serum arginase I levels compared with atopic asthmatic patients and healthy controls although no difference was observed between atopic asthmatic patients and healthy controls. Spearman's correlation analysis showed that serum arginase I level had a significant negative correlation with age and a positive correlation with red blood cell numbers in healthy controls, whereas in asthmatic patients, it had significant positive correlations with alanine aminotransferase (ALT), high-sensitivity C-reactive protein (hs-CRP) and a negative correlation with immunoglobulin-E (IgE). CONCLUSIONS: High serum arginase I levels in asthmatic patients may be associated with airway inflammation in non-atopic asthma.